Atomistic details of charge/space competition in the Ca2+selectivity of ryanodine receptors

Chunhong Liu, Aihua Zhang, Nieng Yan, Chen Song

Research output: Contribution to journalArticlepeer-review

Abstract

Ryanodine receptors (RyRs) are ion channels responsible for the fast release of Ca2+ from the sarco/endoplasmic reticulum to the cytosol and show a selectivity of Ca2+ over monovalent cations. By utilizing a recently developed multisite Ca2+ model in molecular dynamic simulations, we show that multiple cations accumulate in the upper selectivity filter of RyRs, and the small size and high valence of Ca2+ make it preferable to K+ in competition for space in this confined region of negative electrostatic potential. The presence of Ca2+ in the upper selectivity filter significantly increases the energy barrier of K+ permeation, while the presence of K+ has little impact on the Ca2+ permeation. Our results provide the atomistic details of the charge/space competition mechanism for the ion selectivity of RyRs, which ensures the robustness of their Ca2+ release function. The mechanism could be utilized in protein- and nanoengineering for valence selectivity of ion species.

Original languageEnglish (US)
Pages (from-to)4286-4291
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume12
Issue number17
DOIs
StatePublished - May 6 2021

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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